1. Technical Field
The present invention relates to a method for extracting antioxidant from Gracilaria tenuistipitata, and more particularly to a method for enhancing antioxidative ability of Gracilaria tenuistipitata extract.
2. Description of Related Art
Gracilaria tenuistipitata is a large alga of Phylum Rhodophyta, Class Florideophyceae, Order Gigartinales, Family Gracilaria tenuistipitata. It can be found in middle to lower parts of intertidal regions and has a color of greenish brown. It has a size between 15 and 20 cm3, in a column shape or a furcata compressed shape or with flanking meristem. There are about 100 species around the world and they mainly live in the Temperate Zone and the Torrid Zone such as in India, Indonesia, China, Taiwan and Japan. Gracilaria tenuistipitata is rich in carbohydrate and protein, wherein the carbohydrate is mainly polysaccharide. It is one of the major sources of agar, for extracting algin or being used as a food additive. Researches indicate that Gracilaria tenuistipitata can be extracted, through various ways, to obtain active components that promote immune cell proliferation and inhibit mammary, hepatoceluloar and pancreatic carcinoma cells. Its extract also helps with inhibiting growth of human promyelocytic leukemia cells (HL-60), human erythromyeloblastoid leukemia cells (K562), human-human hybridoma cells (HB4C5), human colon adenocarcinoma grade II cells (HT-29) and Human breast adenocarcinoma cells (MCF-7). Phycoerythrin, in a proper amount, is useful in preventing chromosomal mutation and improving immunocompetence. Traditionally, Gracilaria tenuistipitata extract is made by milling and extract a Gracilaria tenuistipitata solution in a mill. With the attempt to enhance the extraction rate of polysaccharide, activated protein and phycoerythrin in Gracilaria tenuistipitata, hot-water extraction has been performed. However, hot-water extraction still fails to achieve satisfying extraction rate of activated protein and phycoerythrin while adversely affecting to biological activity of these components, thus being disadvantageous in practice.